Optimized Design of Silencer - An Integrated Approach

With the stringent legislative requirements for noise in automobiles, gensets etc., the concern for properly designed silencers for specific applications is increasing. Optimized design of silencer requires an integrated study of acoustical and engine performance viz. Insertion loss and backpressure. However, the insertion loss itself depends upon engine characteristics geometry indicated by the transmission loss, flow induced noise, type of silencer - reactive, absorptive, hybrid, etc. Most of the work till date covers the acoustical and engine performance in isolation rather than in an integrated fashion due to the multidisciplinary nature of the problem. The objective of this study is to develop an integrated methodology to predict the performance of the silencer at the design stage resulting in an optimized time and cost effective design. In the present study, the acoustical and engine performance of silencer was predicted using FEM/BEM and CFD techniques. For the validation of the predicted results, an experimental test rig was designed and developed for the determination of transmission loss of silencers. Using the integrated approach, it was possible to optimize the silencer design and meet the two conflicting requirements and reduce the design cycle time.